Quinn, Brittany and Santana are back... and they're wearing Cheerios uniforms. The friends/frenemies, nicknamed "Unholy Trinity," were spotted in behind-the-scenes "Glee" photos at McKinley High School rocking red pleated cheerleading outfits.

According to E! News, Quinn (Dianna Agron), and her cheering pals Brittany (Heather Morris) and Santana (Naya Rivera), were performing a musical number on the McKinley football field with a marching band.

All three ladies wore a cheer outfit with "Cheerio Alum" on the back. So what's the deal? After the girls graduated they all left Lima, Ohio to pursue their dreams. Quinn is a student at Yale, Santana moved to New York City and Brittany was at MIT. We don't think they missed their pop-poms that much.

E! suggests that maybe the trio is back "for a reunion and are taking to the field as Cheerios again for old time's sakes." Agron, Rivera and Morris aren't the only "Glee" originals who are returning for the sixth and final season.

Lea Michelle, Chris Colfer, Darren Criss, Agron, Dot-Marie Jones, Jane Lynch, Kevin McHale, Matthew Morrison, Chord Overstreet, Jenna Ushkowitz and Amber Riley are all coming back. Some even reported that set photos of Michelle (Rachel Berry) and Overstreet (Sam Evans) were spotted on the football field with the "Unholy Trinity."

"My feeling about the last season of 'Glee' is very clear, and that is that we will be reaching out to all of the regulars on the show, that original group of 'Glee' club members and the teachers, and anybody who wants to come back can come back," Murphy previously told E! News. "Anybody who wants to be a part of the show, we welcome them."

"Glee" Season 6 premieres in 2015.